The great Warren Deck presented a clinic on tuba techniques at the Second National T.U.B.A. Symposium in 1980. He had the low brass section of the Houston Symphony Orchestra on stage with him to help demonstrate some of his points.

NOTE to audiences at future events like this. If the presenter says, "Can you hear me without the mic?" and if you are sitting near the front, don't say "Yes." And if you want to ever hear a recording (or allow others to), don't say "Yes." I've done a few restorations of recordings like this one lately, and this was by far the hardest to deal with because of talking sounds that didn't even show up in the wave graph. I was boosting things by 30db in places, and I EQ'd those to boost the male voice range and steeply suppress lows and highs outside that range. Without that, it would have been a real adventure riding the volume control to try to listen!